A large and growing population of users enjoys entertainment through the consumption of digital media items, such as music, movies, images, electronic books, and so on. Users employ various electronic devices to consume such media items. Among these electronic devices are electronic book readers, cellular telephones, personal digital assistants (PDAs), portable media players, tablet computers, netbooks, and the like. These electronic devices wirelessly communicate with a communications infrastructure to enable the consumption of the digital media items. Typically, the communications infrastructure dictates transmit power levels for the electronic devices to use when transmitting data to the communications infrastructure. The electronic devices do not include transmit power managers for making their own determinations regarding what transmit power levels to use.
Some bodies of research suggest that radiation output by electronic devices during wireless transmission of data can cause damage to the human body when such radiation is absorbed. However, since electronic devices lack the ability to control their transmit power levels, such electronic devices cannot adjust their transmit power levels to reduce user exposure to radiation. This may also consequently cause these electronic devices to fail to comply with FCC regulations regarding the specific absorption rate (SAR) permitted to electronic devices. SAR is a measure of the rate at which energy is absorbed by the body when exposed to a radio frequency (RF) electromagnetic field. In addition, the user's body can block the RF electromagnetic field in the direction of the user's body, thus reducing the gain in that direction. This may also cause difficulty in meeting the SAR requirements.
Some electronic devices are capable of connecting with multiple wireless communication infrastructures concurrently. Each such connection to a wireless communication infrastructure causes radiation to be emitted, thus causing such devices to expose users to even greater amounts of radiation.